Clutch



Patented Oct. 21, 1941 UNITED STATES PATENT oFFlcE Clarence M.laovnankesha, Wis.

Application April 27, 1939, Serial N0. 270,283 claims. (ci. .19a-ssiThis application is a continuation-impart of my copending applicationSerial No. 245,601, led December 14, 1938.

The present invention relates to friction clutches of the disc or platetype used for con trolling the transmission of power from a drivingmember to a driven member, and more particularly this invention isconcerned with clutches having a flexibly connected part accommodating agreater amount of misalignment than heretofore. In, most clutchesusually one part is conelated member and its point of attachment tonected'to one ofthe dirving or driven members -I andl the other clutchpart is connected with the other member. When the clutch is engaged.'the parts are held tightly together, and where the driving and drivenmembers are out of accurate alignment with each other during operation,cony proved satisfactoryfor Voperation under condi,

tions of misalignment is shownin my prior Patent No. 2,177,362, issuedOctober 24, 1939, to which reference may be had if desired, and, ingeneraLconsists of a clutch disc having flexible circumferentialyextending fingers, each. connected at its inner end to'the clutch discand at its outer end to the associated driving or driven member. Theclutch disc is thus flexibly connectedtherewith and can accommodateagreater amount of misalignment, particularly angular misalignmentbetweenthe .axes of rotation of the members, than any other prior clutchof this type. It is the object and general nature of this invention toprovide a clutch disc which embodies certain improvements over theconstruction shown in my above mentioned prior Patent No. 2,177,362. Onefeature of this invention is the provision of a clutch disc formedgenerally 'of flat sheet or strip stock and having flexible at tachingfingers each constructed witha greater degree of curvature than thecurvature ofthe periphery-'or circumference 'of the disc 'proper at 'thepoint where the finger is connected to the clutch disc. Thisconstruction results in a much greater longitudinal extensibility ofeach finger;

sible attachingngers in which the major portion ofthe linger liesentirely outside a straight 'line connecting said points of attachment,which line is generally tangent to the disc' proper at the point wherethe nger is connected to the clutch disc.

Another feature of this invention is the provision of a clutch disc orplate in the form of a plurality ot segments each with a exibleattaching finger and each having thegrain of ,the metal running the,same' general direction, preferably longitudinally of the fingers,whereby the characteristics of all of the attaching ilngers,particularly as concerns their resilience and flexibility, are the same.In clutch discs, such as the onevdisclosed in my last mentionedcopending application, where the entire disc and flngers are formed inone piece, it will be seen that in some fingers the grain of the metalruns longitudinally, while in othersthe 'grain runsP transversely.'I'here is' therefore some variation inthe flexibility and extensibilityofthe several fingers, which is avoided by the present invention. 1

These and other objects and advantages of the presentinvention will beapparent to those skilled in the art after a consideration of thefollowing detaileddescription of the preferred embodiment of my`invention, taken' in conjunction with the accompanying drawings, inwhich:

Figure 1' is an axialsection taken along the line I-i of Figure'2,showing a clutch embody- Referring now to Figure 1, the clutch I isadaptedv to be secured to the flywheel 2 of a motor by stud bolts 3. Theflywheel 2 is secured to the flange 4 of the motor crankshaft 5 by studbolts 6. The clutch I includes a driving clutch disc I0, described belowin detail, disposed between a pairof -driven clutch plates Il and I2.The clutch plate Il has an integral hub l'3 secured by a key Il-to adriven shaft I 5, which may be supported for rotation on and form a thatis, the distance for each finger between the l i point of attachment atitsl outer end tothe asso,-

part of the machine (not shown) to be driven by the motor. The otherclutch plate I2 is disposed spring 2| is seated against an aperturedinsulating washer 22. The other end of each spring seats against'acollar 23 which has a plurality of flanged openings 24, the llange ofeach-of which centers the associated spring 2i. A snap ring 25 seats ina groove 26 and holds the collar 23.0n

the hub I3. A hole 21 extends through t-he platev` I2 from the bottom ofeach recess and is in line with a hole 28 in the plate Ii. Thecirculation o'f air through the washer 23 and the registering holes 21and 28 keeps the springs 2| from overheating in operation. The clutchplate I2 is shifted by means of an axially movable member 3I bearingagainst a plate 32 secured by cap screws 33 to the outer ends I1 of thepins I6. An anti-friction thrust ring 34 is disposed between the member3| and the plate 32.

The present invention is not to be limited to shifting mechanism justdescribed, for any suitable shifting means may be used to engage anddisengage the clutch, as desired.

The driving clutch disc IU, as best shown in Figure 2, .comprisesgenerally an inner disc or plate section 35, constituting the clutchdisc proper, and a plurality of generallycircumferentiallyydirectedattaching fingers 36. The disc section 35 consists of'a number ofsegmental parts 3-1, 36, 39, etc., each having two attaching fingers 36.Also, the opposite faces of each segmental part carry clutch lining 4Iof any suitable material secured'thereto by rivets 42, which areinserted through holes 43 ln the clutch` segment.

' As shown in Figure 2, the segments 31, 38, 39, etc.

are four in number and spaced apart only a small amount at theiradjacent edges, so thatV when assembled, as shown, .the segments takentogether form the clutch disc 35. Each segment has lugs 44 at itsradially outer corners, just outside the circumference of the clutchdisc 35, and each lug 44 has a hole 45 drilled therein.' Ad-A jacentholes receive small staples or clips 46 formed of wire .or the likewhich. hold the assembled segments together for handling as a unitduring the attachment of the clutch to the flywheel 2 or other part, andwhich also hold the segments together when in operation.

'Ihe lingers 36 preferably are'formed integral with the associated discsegments, each linger being connected at one end, as at 36a, thereto andat the other end is apertured' and carries al spacer 49 which has alreduced end 50 riveted in the.

opening I at the outer end of the linger. The

llywheel 2 is` drilled and tappedr'as at 54, and,

receives the studbolts 3 which pass through the bushings or spacers 49and secure the outer or free ends of the fingers 36 t0 the flywheel. Thearms or llngers 36 are in the nature of springs since they have therequisite resiliency, and while they are shown as connected integrallyto the clutch disc, they may be made separately .and secured thereto asdesired.

The flywheel normally rotates in the direction ofthe arrow shown inFigure 2, so that the lingers 36 operate normally in tension intransmitting the driving force to the clutch disc`35 and through thelatter and the driven plates II and I2 to the driven shaft I5. Thefingers are llexible laterally l 2,259,461 bout the hub la and has aplurauty of shoulof the plane of the disc and are also particularlyformed to .be extensible in a longitudinal direction and to be capableof a certain amount of deflection generally radially outwardly of thedisc. To this end, each finger is formed as an arc having a radius Rconsiderably shorter than the radiusv of the circumference of the clutchdisc itself. The curvature of each linger is such that the largerportion of the body of the linger lies wholly outside of a line a(Figure 2) connecting the center of the spacer 49 (the point ofapplication of the driving force) and /thefpoint 36a. (the point ofapplication of the load) where the finger joins the disc, the length andposition of the finger 36 being such that the line a is generally atangent at point 36a. This provides the most advantageous application ofthe driving force,

and since practically all of the metal of each finger lies'radiallyoutwardly of the line a, each linger is extensible in the direction ofthe line a to a much greater degree than would be the case if the line apassed through metal for most of its length. In the one. caseextensibility is secured by the link tending to straighten out withsomewhat of a bending action under the forces imposed thereon, but inthelatter case the extensibility available is limited .principally tothe stretch in the metal itself.

The junction 'b where the inner edge of each linger joins the discproper is curved generally in an arc having a radius `r large enough todistribute the stresses over a considerable area when the finger isdeflected generally radially outwardly away from the disc. and thereforethe localization of stresses and possible failure at this point areprevented.

It will be understood that where the driven shaft I5 is in perfect axialalignment with the crank shaft 5 there is no flexing of the fingers inoperation; It is not usual, however, that perfect alignment is retainedfor any length of time even if it was initially present. Under someconditions the axes of the driving and driven parts `may intersect butwith one axis at an angle with relative to the other.

cases, the axes may be both angularly misaligned respect tothe other,and in othercases the two axes may be parallel but one displaced axiallyFurther, in still other and radially displaced. When the driving anddriven members rotate together with the driving clutch disc properclamped tightly between the two driven plates, the driving plate tendsto move bodily with the driven parts of the assemblage, regardless ofthe position of the driving parts. It will be seen, therefore, that withany one of the above mentioned misalignments, each linger 36 goesthrough a cycle of flexing in dilerent directions -for each revolutionof the driving and driven members. If, for example, the driving anddriven members are merely angularly misaligned, resulting in the planeof rotation of the driving clutch disc being cocked relative lto theplane of rotation of the portion of the driving flywheel 2 to. whichthe-outer ends of the fingers 36 are attached, when any one finger is'at the top.

-it will be deflected in one direction, and when it is at the bottom itwill be deflected in the opposite direction, both generally laterallywith respect to the plane of the lingers. Further, each linger will alsobe deflected generally radially a points adjacent the axis about whichthe cooking takes place there is a slight variation in the disfingerlies above or radially outwardly of the line extending generallytangentially from the point of connection of each finger to the flywheelto the point where the finger joins the clutch disc proper, secures anamount of longitudinal extensibility sufiicientrto accomodate aconsiderable degree of angular misalignment, as well as generally radialdisplacement,A and the relatively large curvature, as indicated at b,serves to prevent any localization of the stresses 'at the points wherethe inner edge of each finger joins the clutch disc proper. Further, thelength of each finger from its point of attaclunent. at 36a, to theldisc to the bushing 43 is sufiicient to provide the requisite lateralflexibility to accommodate a considerable axial displacement of theplane of rotation of the disc relative to the plane of rota-V tion ofthe points on the flywheel where the outer ends of the fingers arebolted thereto. Where each finger thus passes successively through vari`ous positions'and is flexed and distorted to various degrees when thedriving and driven parts are misaligned, it will be seen that it isimportant to form the clutch disc so that all of the fingers have aboutthe same degree of flexibility and extesibility. To this end, thepresent invention therefore contemplates manufacturing the clutch disc,not as one integral plate, but in the form of a plurality of segmentalsections with the grain Similar deflections take i i 3 linings withoutdisturbing or disconnecting the driving and driven parts. To do this, itis merely .necessary 'to hold the ,clutch disengaged, as

. flywheel 2, in the manner shown in Figure 1 of the metal runningsubstantially the same way in each resilient armor finger, thereibeingfour segmental sections 31, 36, 33, and 40 as described above. Thenumber of segments may, ofcourse, vary. The several sections are'arranged and assembled so that, taken togethenthey comprise the clutchdisc by which power is transmitted f from the driving t0 the drivenelements.

When the clutch is assembled and connected between the driving anddriven parts 2 and i6, the xed clutch plate ,Il is fixed to the shaft I5in such a position that when the other clutch ofthe plate Ii and thethickness of the washers or bushings '43. vThe purpose of 'thisarrangement is to bias the spring arms 36 so that they move the clutchdisc proper out of engagement with the fixed driven clutch plate il whenthe materially contributes to the accessibilityof the attaching/bolts 3and therefore makes itv feasible to renew they clutch in this manner. Incases where the clutch is disposed within the body of the flywheelitself, itis sometimes inconvenient, if not impossible, to reach theclutch disc or the attaching bolts.

Referring now'to Figure 3, the reference numeral 66 indicates the stripof stock from whidh the clutch segments 3l, 33, etc., are formed, thestrip being of sheet metal of uniform thickness. The grain of the metalin this strip 60 runs longitudinallythereof, and each of the segments iscut from the strip in such a waythat the fingers 36 extend generallylongitudinally of the strip 60, whereby the grain in each of the fingersruns generally longitudinally thereof. Thus, each finger has about thesame characteristics of elasticity and extensibility as each of theother fingers of the clutch disc.

In addition to the advantage of having the grain of the metal runlongitudinally in substantially the same manner for each of the fingers36,

, punching the segments from a narrow strip also makes it possible toconstruct the clutch with only a small amount of waste especially ascompared with the amount of Vwaste that would occur if the discs werecut or punched as an integral part from a strip of metal'as wide as the,overall diameter of the discand fingers together. Further, thesegmentscan be formed on a press smaller than thepress that would berequired to punch the entire disc at one stage.

According to the present-invention, the segments are-formed in twostages. holes 43, the holes 6I receiving the bushings, and the holesdefining the space. between the arms or fingers 36 and the body of the-disc 35 are punched, as indicated in full lines in the right handportion of Figure 3. Next, this portion of the stock is advanced to theleft, and the segment is completed by punching out the remainder of thematerial, as shown in the left hand part of Figure 3. 'To performbothoperations simultaneously, a first punch'and die set is provided to setsvare attached' to the press in such a way that clutch is released,thereby eliminating any possitially. directed fingers 36; it is possibleby remov ing one segment at a time and replacing' it with a new orreconditioned one to renew the clutch each Voperation of the press,after the feeding of lthe strip has been started and'is continuous,

punches the rivet holes and the other holes mentioned at the same timethat. the pilgrimagex iately preceding section is punchedatovcompl'eteffi:the

segment. Theiholes 43 may be drilled as aflateryvlk operation, ifdesired. The holes M preferably arey f drilled, since they are ofrelatively small diamef- First, the rivet full driving iorcebut isexceedingly flexible and can accommodate axial, radial, or angularmisalignment,` or anyy combination of vmisalignments for transmittingthe' full load and withoutl causing any parts of the clutch'to slip'oroverheat. Further, the'particular form of flexible connecting armswithwhicli the present disc clutch is provided makes it, possible tosecure the requisite ii'exibility without overstressing the metal `ofthe arms or the metal at the points where the arms join 'orconnect tothe clutch disc proper. I Specifically, I secure the desired amount offlexibility by vforming the attaching arms or ngers with arcuateAsections s'o that the main body of the finger lies outwardly of a lineconnecting the outer end of the finger to the point oi its attachment tothe disc. The present invention also provides an improved clutchconstruction by dividing the clutch disc proper into a plurality ofsegments,l which not only makes it possible to replace or renew theclutch surfaces without disassembling the driving and driven parts, butalso it is possible to form the clutch segments on a smaller press, andthereby at less cost, and to havethe grain of the metal runsubstantially the same way in each of the attaching fingers.

It is to be understood that my invention is not to be limited to thespecific details shown and described above, but that, in fact, widelydifferent means may be employed in the practice of the broader aspectsof my invention.

What I claim, therefore, and desire to secure by Letters Patent is:

1. A clutch disc comprising a plurality of segmental sections and one ormore generally circumferentially directed arcuate attaching fingersapertured, and spacing bushings fixed to the freeends of said fingers,each bushing having a reducedend riveted in the aperture at the free endofthe associated finger.

v3.,.A51- clutch adapted to connet driving and gdrivengparts, comprisinga clutch disc consisting a ofv a plurality of segmental members, eachhaving at its periphery one' or more generally circumferentiallyextending flexible arms, one of the ...arms of each segmental memberbeing formed on .an arcuate curvature of smaller radius than saidsegmental member, means fixing the free ends of said arms to one of saidparts, and a pair of clutch plates carried by the other of said partsfor clamping said segmental members therebetween.

4. A new article of manufacture comprising a clutch disc formed of aplurality of metallic segmental plates, the peripheral portion of eachplate having one or more generally circumferentially extending arms,said arms being formed on an arcuate curvature of smallerradius -thansaid segmental plates, each of said plates being formed so that thegrain of the metal extends approximately in the same direction in all ofthe arms of the clutch disc.

5. A clutch disc comprising a plurality of segmental sections, eachhaving one or more generally circumferentially directed arcuateattaching fingers integrallyrgonnected at one endto the aantal.

associated section,l eadh section being formedof sheetmetal stock withthe grain of the metal extending generally longitudinally in eachattaching finger whereby the resilience of. each finger is substantiallythe same as that of the other fingers- 6. A clutch disc having aplurality of arcuate attaching arms connected thereto at one end, theother end being free; the radius of curvature4 of each arm being suchthat the principal portion of the body of the arm lies wholly outside aline extending from the end -of the arm to its connection to said disc.

7. A clutch disc comprising al plurality of segmental sections, eachhaving a plurality oi' arcuate attaching arms connected thereto at' oneend, the other ends of said arms being free, the free end of each armbeing apertured to receive attachment means and the aperture of each armbeing disposed in a line substantially tangent to the disc at the pointwhere the arm connects therewith. l 8. A clutch disc as dened in claim 7wherein the radially inner edge of each arm is curved from one end ofthe arm to the other and lies radially outwardly of said tangent line.

9. A clutch adapted to connect driving andi driven parts, comprising aclutch disc having`a plurality vof resilient attaching arms, eachconnected at one end to the disc and extending generallycircumferentially therefrom in the general plane thereof, a pair ofclutch plates, one xed to one of said parts and the other movablerelative to the fixed clutch plate for clamping the clutch disctherebetween, and means for attaching the free ends of said resilientarms to the other part, said rst clutch plate and said free ends of saidarms being attached, respectively, to said parts at such points thatwhen the clutch disc is clamped between the clutch plates said resilientarms are deflected out of their normal position and will move the clutchdisc away from said fixed clutch plate when the other clutch plate isshifted to disengage the clutch.

10. A clutch to connect a flywheel anda driven shaft, comprising a pairof driven clutch plates carried by said driven shaft adjacent the planeof the outer edge of said ywheel, a driving clutch disc disposed betweensaid plates and formed as separately removable segmental sections,fiexible arms projecting from the outer peripheral portions of saidsegmental sections for separately connecting each' segmental section tothe outer edge of said flywheel, said arms being releasable from saidflywheel'to provide for the separate removal of said sections radiallyoutwardly from betweensaid plates alongside the outer edge of saidflywheel, and means effective between adjacent segmental sections forlimiting outward radial movement of one of said sections relatively toan adjoining section.

11. A clutch disc comprising a plurality of arcuate segmental partshaving their adjacent edges :extending substantially radially of thedisc, said segmental parts being assembled in generally circularformation to form the clutch disc, circumferentially extending flexiblearms projecting from the outer peripheral portions of said segmentalparts for mounting said parts in the clutch, each segmental part havingan apertured lug at the4 radially outer corners, and a link disposed inthe apertures of adjacent lugs shaft, comprising a pair of drivenclutchlplates carriedby said driven -shaft adjacent the plane of theouter edge of said fly wheel, a driving clutch disc disposed betweensaid plates and formed as separately removable segmental sec? tions,`each of said segmental sections having a plurality of arcuate attachingarms connected thereto at one end, the other ends of said arms be by theother rotary member, said clutch disc comwardly from the periphery ofthe segment, means ing free, the radius of curvature of each arm beingsuch that the principal portion of the.b0dy of the arm lieswhollyoutside la, line extending from the end of the arm to its. connectionto' said segmental section, means separately connecting each attachingarm to the outer edgeof said fly wheel, said means being removable toprovide for the separate removal of said sections radially outwardlyfrom between said plates alongside the outer edge of said flywheel; andmeans effective between adjacent segmental sections for limiting outwardradial movement of one of said sections relatively to an adjoiningsection.

13. In a clutch adapted to connect tworotary members, the lcombinationof a clutch disc carried by one of said rotary! members andladapted toengage a cooperating clutch element carried by the other rotary member,said clutch disc comprising a plurality of segmental sections separatelyremovable and replaceable in the clutch assembly, each of said segmentscomprising a plurality of attaching arms extending in a generallycircumferential direction from the periphery of the segments, means forattaching said for attaching said free ends to one of said rotarymembers, and tie means extending between the adjoining -edges ofadjacent segments anddis-` posed adjacent the peripheries of saidsegments inside the lfree ends ofadjacent attaching arms,

said tie means resisting'circumferentialseparating forces acting betweenthe segments While permitting relative radial movement between thesegments.

s having their contiguous or meeting edges Vextendarms to one of saidrotary members, and means establishing a tie connection between theadjoining edges circumferential vseparating 'forces between the segmentswhile permitting relative radial movement between the segments,

-14. In a clutch adapted to connect of adjacent segments such as resists1 Y two rotary members, the combination of a clutch disc'caringsubstantially radially of the disc, a pair of flexible attaching armsforeach segment having their inner `ends formed integrally with thesegments andl having their free ends extending in a generallycircumferential direction spaced outwardly from the periphery of thesegments, bolts securing said free ends-tothe outer edge of saidflywheel, and tie means extending between the adjoining edges ofadjacent segments and disposed adjacent the peripheries of said segmentsinside the free ends of adjacent attaching arms,

^ said tie means increasing the hoop strength of the assembly f segmentswhile permitting relative radial movement between the segments.

CLARENCE M. EASON.

